Method of preserving and treating paper pulp



Patented Feb. 12, 1924.

UNITED STATES JUDSON A. DE CEW, OF MOUNT VERNON, NEW YORK, ASSIGNOR TO PROCESS GINEERS INCORPORATED, OF NEW YORK, N. Y.

PATENT OFFICE.

METHOD OF PRESERVING AND TREATING PAPER PULP.

No Drawing.

To all whom it may concern:

Be it known that I, Jonson A. DE Cnw, a citizen of Canada, residing at Mount Vernon, New York, have invented certain new and useful Improvements in Methods of Preserving and Treating Paper Pulp, of which the following is a specification.

This invention relates to methods of preserving and treating paper pulp and it consists essentially in coagulating the soluble mucilaginous or colloidal matters in the paper pulp with an agent which is at the same time a preservative.

I have discovered a method of improving the quality of the paper which consists in preserving the pulp from fermentation during the process of manufacture and at the same time coagulating the soluble mucilaginous matters present by either accident or design within the pulp.

Paper pulp is in general not sterilized in t e process of manufacture and as a result, jell-like masses form wherever the pulp lodges in pipes or tanks, and when they dislodge, masses of slime cause serious difficulties with the paper machine besides producing many blemishes in the paper.

In most pulp stock there is soluble mucilaginous material which is especially appar- 80 out in mills using waste paper.

I have discovered that a solution of formaldehyde used in small quantities will not only prevent fermentation in the pulp but will coagulate most of the soluble mucilag- 86 inous material present and increase the retention of it in the paper. The result of this treatment is a harder and snappier paper and there is less difiiculty on the paper machine.

In applying this process, I add to the beater or mixing tank, a solution of formaldehyde in the proportion of approximately one pound formaldehyde to one thousand Application filed August 24, 1921. Serial No. 495,096.

pounds of paper stock. I The stock so treated improves with age instead of undergoing much cleaner paper can be made because the pulp does not stick to the pipes and tanks. When paper stock is acid with the alum used in sizing it, it is much more likely to ferment than at other times and under such conditions, this process is very, important also. Cross reference is made to my application, Serial No. 495,097, which was patented December 27, 1921, as Patent No. 1,401,525.

What I claim as my invention is:

1. A method of preserving and hardening paper which 'consistsin adding to the pulp a solution of formaldehyde and completely mixing it with the pulp before passing the pulp to the papermachine;

2. A method of preserving and hardening paper which consists in treating the paper pulp with a solution of formaldehyde in the proportions of approximately one pound of lformaldehyde to one thousand pounds of pu p.

3. A method of preserving paper pulp containing alum from fermentation which consists in incorporating into the mixture of pulp and water a small quantity of formaldehyde solution.

4. A method of preserving and hardening paper which consists in coagulating the soluble mucilaginous matters in the pulp with a coagulating agent which is at the same time a preservative.

In testimony whereof I have aflixed my signature to this specification.

JUDSON A. DE CElV. 

